FAQ|V4.3.5|OceanBase Database| docs|Distributed Database

This topic describes the general issues that may occur when you use TableAPI, including their causes and solutions.

General issues in using the IDEA tool

ObTableClient Jar package missing

Exception in thread "main" java.lang.NoClassDefFoundError: com/alipay/oceanbase/rpc/ObTableClient
 at com.oceanbase.example.KVClient.initial(KVClient.java:46)
 at com.oceanbase.example.SimpleKVDemo.main(SimpleKVDemo.java:25)
Caused by: java.lang.ClassNotFoundException: com.alipay.oceanbase.rpc.ObTableClient
 at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
 at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
 ... 2 more

Process finished with exit code 1

Cause

The obkv-table-client dependency package specified in the pom.xml project file is missing. The possible cause is that the dependency package is not downloaded to the local mvn repository. The complete path of the client jar package is as follows:
```
～/.m2/repository/com/oceanbase/obkv-table-client/0.1.0/obkv-table-client-0.1.0.jar
```
Solution

You can check whether the address of the local repository is configured in IDEA based on the following figure:

Java client initialization failed

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See https://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Sofa-Middleware-Log:WARN [oceanbase-table-client] No log util is usable, Default app logger will be used.
... ...
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Access denied for user 'proxyro'@'xxx.xxx.xxx.xxx' (using password: YES)
 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
 at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
  ... ...

Cause

In the example, no password is set for the proxyro user. That is, no password is set for the user specified by the setSysUserName function during client initialization.
```
obTableClient.setSysUserName("proxyro@sys"); // e.g. proxyro@sys
obTableClient.setSysPassword("proxyro@passwd");
```
Solution

You can log in to the OceanBase cluster by using OBClient or a MySQL client, and then run the following command to set a password for the proxyro user. For more information, see Connect to an OceanBase tenant by using OBClient and Connect to an OceanBase tenant by using a MySQL client.
```
grant select on oceanbase.* to proxyro identified by 'xxx';
// 'xxx' is the password.
```

Database empty

java.lang.IllegalArgumentException: database is empty. url=http://ip:port/services?Action=ObRootServiceInfo&User_ID=admin&UID=admin&ObRegion=ocp
 at com.alipay.oceanbase.rpc.ObTableClient.setParamURL(ObTableClient.java:1396)
 at com.oceanbase.example.KVClient.initial(KVClient.java:48)
 at com.oceanbase.example.SimpleKVDemo.main(SimpleKVDemo.java:25)
fail to init KV client, java.lang.IllegalArgumentException: database is empty. url=http://ip:port/services?Action=ObRootServiceInfo&User_ID=admin&UID=admin&ObRegion=ocp

Cause

No database is specified in the input URL of the setParamURL function when the Java client is initialized.

Solution

You can specify the database to access in the URL.

obTableClient.setParamURL("http://ip:port/services?Action=ObRootServiceInfo&User_ID=xxx&UID=xxx&ObRegion=xxx&database=test");

Table does not exist

com.alipay.oceanbase.rpc.exception.ObTableNotExistException: table not exist: kv_table
 at com.alipay.oceanbase.rpc.location.LocationUtil.getTableEntryFromResultSet(LocationUtil.java:622)
 at com.alipay.oceanbase.rpc.location.LocationUtil.getTableEntryFromRemote(LocationUtil.java:384)
 at com.alipay.oceanbase.rpc.location.LocationUtil.access$200(LocationUtil.java:50)
 at com.alipay.oceanbase.rpc.location.LocationUtil$1$1.execute(LocationUtil.java:313)
 at com.alipay.oceanbase.rpc.location.LocationUtil$1$1.execute(LocationUtil.java:309)
 at com.alipay.oceanbase.rpc.location.LocationUtil.callTableEntryRefresh(LocationUtil.java:264)
 at com.alipay.oceanbase.rpc.location.LocationUtil.access$300(LocationUtil.java:50)
 at com.alipay.oceanbase.rpc.location.LocationUtil$1.execute(LocationUtil.java:308)
 at com.alipay.oceanbase.rpc.location.LocationUtil$1.execute(LocationUtil.java:305)
 at com.alipay.oceanbase.rpc.location.LocationUtil.callTableEntryRefreshWithPriority(LocationUtil.java:133)
 at com.alipay.oceanbase.rpc.location.LocationUtil.loadTableEntryWithPriority(LocationUtil.java:304)
 at com.alipay.oceanbase.rpc.ObTableClient.refreshTableEntry(ObTableClient.java:753)
 at com.alipay.oceanbase.rpc.ObTableClient.getOrRefreshTableEntry(ObTableClient.java:702)
 at com.alipay.oceanbase.rpc.ObTableClient.getTable(ObTableClient.java:839)
 at com.alipay.oceanbase.rpc.ObTableClient.execute(ObTableClient.java:424)
 at com.alipay.oceanbase.rpc.ObTableClient.execute(ObTableClient.java:400)
 at com.alipay.oceanbase.rpc.ObTableClient.insert(ObTableClient.java:1060)
 at com.alipay.oceanbase.rpc.table.AbstractTable.insert(AbstractTable.java:52)
 at com.oceanbase.example.KVClient.put(KVClient.java:81)
 at com.oceanbase.example.SimpleKVDemo.main(SimpleKVDemo.java:40)
fail to put kv data, com.alipay.oceanbase.rpc.exception.ObTableNotExistException: table not exist: kv_table

Cause

The kv_table table does not exist in the database specified by setParamURL.

Notice

kv_table is for reference only. The actual table name will be different.
Solution

Ensure that the table being operated by the client API exists in the database specified by setParamURL.

General issues in command line-based development

Dependency packages such as sofa cannot be found

$mvn compile -e
[INFO] Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building simple-kv-demo 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[WARNING] The POM for com.oceanbase:obkv-table-client:jar:0.1.0 is invalid, transitive dependencies (if any) will not be available, enable debug logging for more details
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ simple-kv-demo ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /home/admin/github/obkv-table-client-java/example/simple-kv-demo/src/main/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ simple-kv-demo ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 3 source files to /home/admin/github/obkv-table-client-java/example/simple-kv-demo/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /home/admin/github/obkv-table-client-java/example/simple-kv-demo/src/main/java/com/oceanbase/example/LoggerFactory.java:[21,35] package com.alipay.sofa.common.code does not exist
[ERROR] /home/admin/github/obkv-table-client-java/example/simple-kv-demo/src/main/java/com/oceanbase/example/LoggerFactory.java:[22,34] package com.alipay.sofa.common.log does not exist
[ERROR] /home/admin/github/obkv-table-client-java/example/simple-kv-demo/src/main/java/com/oceanbase/example/LoggerFactory.java:[23,17] package org.slf4j does not exist
[ERROR] /home/admin/github/obkv-table-client-java/example/simple-kv-demo/src/main/java/com/oceanbase/example/LoggerFactory.java:[28,19] cannot find symbol
  symbol:   class LogCode2Description
  location: class com.oceanbase.example.LoggerFactory
[ERROR] /home/admin/github/obkv-table-client-java/example/simple-kv-demo/src/main/java/com/oceanbase/example/LoggerFactory.java:[31,19] cannot find symbol
  symbol:   class Logger
  location: class com.oceanbase.example.LoggerFactory
[ERROR] /home/admin/github/obkv-table-client-java/example/simple-kv-demo/src/main/java/com/oceanbase/example/LoggerFactory.java:[38,19] cannot find symbol
  symbol:   class Logger
  location: class com.oceanbase.example.LoggerFactory
[ERROR] /home/admin/github/obkv-table-client-java/example/simple-kv-demo/src/main/java/com/oceanbase/example/LoggerFactory.java:[28,45] cannot find symbol
  symbol:   variable LogCode2Description
  location: class com.oceanbase.example.LoggerFactory
[ERROR] /home/admin/github/obkv-table-client-java/example/simple-kv-demo/src/main/java/com/oceanbase/example/LoggerFactory.java:[35,16] cannot find symbol
  symbol:   variable LoggerSpaceManager
  location: class com.oceanbase.example.LoggerFactory

org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project simple-kv-demo: Compilation failure
    at org.apache.maven.lifecycle.internal.MojoE

Cause

The jar package that pom.xml depends on in the local path is not of the latest version.
Solution

Clear the local mvn repository package that the project depends on, and perform compilation again.
```
mvn dependency:purge-local-repository
```

Considerations

If you directly use the demo project on the official website of GitHub for debugging, package all dependencies of the demo project before execution. To package all dependencies, you must modify the pom.xml file of the demo project.

Take obkv-table-client-java/example/simple-kv-demo as an example, add the following content to the pom.xml file:

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-assembly-plugin</artifactId>
                <version>2.4.1</version>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                    <archive>
                        <manifest>
                            <mainClass>com.oceanbase.example.SimpleKVDemo</mainClass>
                        </manifest>
                    </archive>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
          <goals>
            <goal>single</goal>
          </goals>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

Compile the package again after modification:

mvn clean package

Run the following command:

java -cp ./target/simple-kv-demo-1.0-SNAPSHOT-jar-with-dependencies.jar com.oceanbase.example.SimpleKVDemo

Note

For more information about demo projects, see example.

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